Under pathological conditions such as secretory or acute otitis media in the middle ear the mucus produced by its muco-ciliary system may accumulate instead of clear. This study is concerned with the factors governing the clearance of mucus by ciliated mucosa in the middle ear and other cavities (sinuses, lungs) similarly lined. The approach is based on our demonstration of the essential physiological role of the mucus itself in this process. The rheological and physico-chemical properties of mucus, in a highly specific manner, determine its ability to convert the ciliary beat into transport, both of itself and of such cellular debris and pollutionary material as is caught up in it. This role of mechanical coupler is determined by its composition and structure, particularly by the super molecular structure and interactions of the mucus contained glycoproteins. Our approach is based on the characterization of the macromolecular fragments of the mucus substance and establishing their role in determining the specific rheological properties of mucus. For this purpose we have developed a biological test system, the ciliated mucosa covered palate of the from which can be detached and depleted of mucus without affecting ciliary beat. On this palate normal homologous mucus completely restores transport of added loads and the effectiveness of mucus samples from other, heterologous sources or substitutes to restore transport can be quantitatively evaluated. We have build a force "clamp" probe to determine the mechanical characteristics of mucs on the mucosa itself, under normal and patholoically varied conditions. This technique is to be used to test and develop remedial treatments and drugs. Studies of growth and differentiation in organ and tissue culture of relevant adults epithelia, including human middle ear mucosa, are being undertaken in order to elucidate the environmental factors which control epithelial growth, differentiation and mucus production.